Eli was 33 years old when she was diagnosed with stage 2 breast cancer in 2006.

Thankfully, investigations did not show any evidence of cancer spread.

As the tumour was small, she had the option of removing the whole breast (a mastectomy) or only the part of the breast with the cancer (partial mastectomy or wide excision).

Going by a clinical examination, the lymph nodes appeared to have been affected, hence all the lymph nodes in the axilla or armpit had to be removed - known as an axillary clearance - at the same time.

Eli opted for a wide excision with axillary clearance and this was carried out in August 2006.

After the procedure, it was confirmed that the tumour measured 2cm across, and only one of the 17 axillary lymph nodes that were removed contained cancer cells.

The cancer cells stained positive for both oestrogen and progesterone receptors.

This means that the cancer cells were, to some extent, "driven" by hormones.

After the surgery, she went for eight cycles of chemotherapy.

She also received radiotherapy to her breast as this is a requirement for patients who opt not to have a mastectomy.

By March the following year, Eli was essentially done with the major part of her treatment.

As she had hormone-receptor positive breast cancer, she was prescribed Tamoxifen, an anti-oestrogen tablet, to be taken daily.

She came back for follow-up reviews every three to four months, and took Tamoxifen till March 2012, when we discussed various options.

One was to continue taking the medication.

Another was to switch to an enhanced hormone therapy which involved injections to stop her menses completely.

Data suggests that stopping her menses completely would offer better control of her disease and lower the risk of relapse.

The last option was to stop hormone therapy and do nothing.

Eli had a son who was 31/2 years old when she was first diagnosed with breast cancer.

The child was conceived after she had gone for in-vitro fertilisation treatment.

One of the reasons Eli wanted to stop taking Tamoxifen after five years was that she was considering having a second child.

Conceiving while on the medication is discouraged as it may affect the baby.

She opted to stop all hormonal therapy at that time as she wanted to try for another baby even though there was no certainty that she would be able to conceive again.

Factors against her getting pregnant included the fact that she had undergone extended chemotherapy; her age, as she was already 40 years old; and that she needed help to conceive the first time round, when she was only 30 years old.

She told me of her pregnancy when she came for her follow-up visit in March last year.

Naturally, she was very happy.

In July last year, she gave birth to a baby girl. With one boy and one girl, she felt blessed and complete.

When she came to see me four months later in November, she had stopped breastfeeding.

It was time for her annual check-up, which consisted of mammogram, chest X-ray, ultrasound and bone scan.

All was well.

Busy with the newborn baby, Eli missed her regular follow-up appointments and showed up again only in June this year.

At first, I was not too perturbed by the delay.

After all, she had remained cancer-free for almost nine years since her surgery.

But the moment I felt her neck, I knew there was trouble.

I felt two tiny lymph nodes, each measuring 0.5cm across, just above her left collarbone.

When I broke the bad news that this could be cancer recurrence, Eli was shocked and devastated.

This was confirmed after a positron emission tomography-computed tomograph (PET-CT) scan. A fine needle aspiration of the lymph nodes also showed cancer cells.

Eli is back on treatment again.

Why did this happen?

Isn't a person who has been cancer-free for five years after treatment supposed to be cured?

Did her pregnancy cause her cancer to relapse?

Yet there are many breast cancer survivors who have had children after completing their cancer treatment and never relapsed.

How long does one need to wait after cancer treatment to conceive safely?

First, one must understand that despite the surgery, chemotherapy, radiotherapy and five years of Tamoxifen, we did not manage to eradicate all the breast cancer cells in Eli's body.

If we had eradicated all the cancer cells, she would not have suffered a relapse.

Her pregnancy did not cause her to relapse. However, it likely accelerated the relapse.

Even if she had not become pregnant, the likelihood is that some time in the future, her cancer would still return.

The flush of hormones during her pregnancy may have played a part in driving the growth of the cancer cells which remained in her body.

Breast cancer is well known to have the ability to relapse after five, 10 or even 15 years after the initial diagnosis.

Does it mean that breast cancer survivors must never get pregnant?

I don't think so.

But it is important for patients to understand the risks associated with pregnancy and choose for themselves what is important to them.

For Eli, the focus now is not just on the why, but also on the need to get well, not just for herself, but also for her two young children.

Follow ST

The Straits Times

We have been experiencing some problems with subscriber log-ins and apologise for the inconvenience caused. Until we resolve the issues, subscribers need not log in to access ST Digital articles. But a log-in is still required for our PDFs.